The objective of the research is to study the factors which control the secretion of peptide hormones by the fetal pituitary, steroid hormones by the fetal adrenal glands and the formation and metabolism of prostaglandins and thromboxanes by fetal tissues. We have developed methods for the isolation and purification of peptides from tissues and have applied these to anterior and posterior lobe of the rat pituitary. We have isolated ACTH1-38 from the anterior pituitary and two forms of alpha-MSH (normal and diacetylated) and two forms of CLIP (ACTH18-39) one of which is normal and one which is phosphorylated on the serine at position 31. We are now studying the biosynthesis of ACTH1-38 in the 31K precursor and the enzymic processing of the precursor to yield the peptide. We are also investigating the O-phosphorylation in the biosynthetic process. We have also been studying the effect of protein-deprivation in the mother on lung maturation in the rat fetus. We have been using dexamethasone binding to the cytoplasmic receptor in liver and lung as an index of tissue maturation along with the incorporation of labelled choline into lecithin. We have also been using the diabetic rat model (streptozotocin) to determine the effect of hyperinsulinism on the development of the fetal lung.